Hundreds of Syrians cross the border into Jordan every day on foot. Some are the elderly walking with children and grandchildren, leaving a lifetime behind them. Others are infants cradled in their parents' arms, too young to remember home. The refugees leave everything behind: savings, houses, pets, clothes, the fresh graves of their loved ones.

As the Syrian civil war enters its fourth year, there are more than 580,000 refugees in Jordan in both formal camps and ...